Fix clearing trigger of events with no sentrees (#5426)

Signed-off-by: Arkadiusz Kozdra <akozdra@antmicro.com>

src/V3Delayed.cpp

@@ -720,9 +720,18 @@ class DelayedVisitor final : public VNVisitor {
     void visit(AstFireEvent* nodep) override {
         UASSERT_OBJ(v3Global.hasEvents(), nodep, "Inconsistent");
         FileLine* const flp = nodep->fileline();
+
+        AstNodeExpr* const eventp = nodep->operandp()->unlinkFrBack();
+
+        // Enqueue for clearing 'triggered' state on next eval
+        AstTextBlock* const blockp = new AstTextBlock{flp};
+        blockp->addText(flp, "vlSymsp->fireEvent(", true);
+        blockp->addNodesp(eventp);
+        blockp->addText(flp, ");\n", true);
+
+        AstNode* newp = new AstCStmt{flp, blockp};
         if (nodep->isDelayed()) {
-            AstVarRef* const vrefp = VN_AS(nodep->operandp(), VarRef);
+            AstVarRef* const vrefp = VN_AS(eventp, VarRef);
-            vrefp->unlinkFrBack();
             const std::string newvarname = "__Vdly__" + vrefp->varp()->shortName();
             AstVarScope* const dlyvscp = createNewVarScope(vrefp->varScopep(), newvarname, 1);
 
@@ -736,24 +745,17 @@ class DelayedVisitor final : public VNVisitor {
             {
                 AstIf* const ifp = new AstIf{flp, dlyRef(VAccess::READ)};
                 postp->addStmtsp(ifp);
-                AstCMethodHard* const callp = new AstCMethodHard{flp, vrefp, "fire"};
+                ifp->addThensp(newp);
-                callp->dtypeSetVoid();
-                ifp->addThensp(callp->makeStmt());
             }
 
             AstActive* const activep = createActiveLike(flp, m_activep);
             activep->addStmtsp(prep);
             activep->addStmtsp(postp);
 
-            AstAssign* const assignp = new AstAssign{flp, dlyRef(VAccess::WRITE),
+            newp = new AstAssign{flp, dlyRef(VAccess::WRITE),
-                                                     new AstConst{flp, AstConst::BitTrue{}}};
+                                 new AstConst{flp, AstConst::BitTrue{}}};
-            nodep->replaceWith(assignp);
-        } else {
-            AstCMethodHard* const callp
-                = new AstCMethodHard{flp, nodep->operandp()->unlinkFrBack(), "fire"};
-            callp->dtypeSetVoid();
-            nodep->replaceWith(callp->makeStmt());
         }
+        nodep->replaceWith(newp);
         VL_DO_DANGLING(nodep->deleteTree(), nodep);
     }
 

src/V3EmitCSyms.cpp

@@ -550,22 +550,19 @@ void EmitCSyms::emitSymHdr() {
 
     if (v3Global.hasEvents()) {
         if (v3Global.assignsEvents()) {
-            puts("void enqueueTriggeredEventForClearing(VlAssignableEvent& event) {\n");
+            puts("void fireEvent(VlAssignableEvent& event) {\n");
         } else {
-            puts("void enqueueTriggeredEventForClearing(VlEvent& event) {\n");
+            puts("void fireEvent(VlEvent& event) {\n");
         }
-        puts("#ifdef VL_DEBUG\n");
+        puts("if (VL_LIKELY(!event.isTriggered())) {\n");
-        puts("if (VL_UNLIKELY(!event.isTriggered())) {\n");
-        puts("VL_FATAL_MT(__FILE__, __LINE__, __FILE__, \"event passed to "
-             "'enqueueTriggeredEventForClearing' was not triggered\");\n");
-        puts("}\n");
-        puts("#endif\n");
         if (v3Global.assignsEvents()) {
             puts("__Vm_triggeredEvents.push_back(event);\n");
         } else {
             puts("__Vm_triggeredEvents.push_back(&event);\n");
         }
         puts("}\n");
+        puts("event.fire();\n");
+        puts("}\n");
         puts("void clearTriggeredEvents() {\n");
         if (v3Global.assignsEvents()) {
             puts("for (auto& event : __Vm_triggeredEvents) event.clearTriggered();\n");

src/V3SenExprBuilder.h

@@ -192,14 +192,6 @@ class SenExprBuilder final {
                 AstCMethodHard* const clearp = new AstCMethodHard{flp, currp(), "clearFired"};
                 clearp->dtypeSetVoid();
                 ifp->addThensp(clearp->makeStmt());
-
-                // Enqueue for clearing 'triggered' state on next eval
-                AstTextBlock* const blockp = new AstTextBlock{flp};
-                ifp->addThensp(blockp);
-                const auto add = [&](const string& text) { blockp->addText(flp, text, true); };
-                add("vlSymsp->enqueueTriggeredEventForClearing(");
-                blockp->addNodesp(currp());
-                add(");\n");
             }
 
             // Get 'fired' state

test_regress/t/t_event.v

@@ -18,6 +18,7 @@ module t(/*AUTOARG*/
 
    event e1;
    event e2;
+   event e3;
 `ifndef IVERILOG
    event ev [3:0];
 `endif
@@ -50,16 +51,21 @@ module t(/*AUTOARG*/
             if (last_event != 0) $stop;
             -> e1;
             if (!e1.triggered) $stop;
+            if (e3.triggered) $stop;
+            -> e3;
+            if (!e3.triggered) $stop;
          end
          11: begin
             if (last_event != 32'b10) $stop;
             last_event = 0;
+            if (e3.triggered) $stop;
          end
          //
          13: begin
             if (last_event != 0) $stop;
             ->> e2;
             if (e2.triggered) $stop;
+            if (e3.triggered) $stop;
          end
          14: begin
             if (last_event != 32'b100) $stop;